Wireless transmission of energy



E. C. HANSON. WIRELESS TRANSMISSION OF ENERGY.

APPLICATION FILED MAY 25. 19H]- 1 3 1 5, 1 97-. Patented Sept. 2, 1919.

Inc '6/220 2" 274.5] amaa/v M NITED STATES PATENT OFFICE.

EARL C. HANSON, OF LOS ANGELES, CALIFORNIA, ASSIGNOR TO TITLE INSURANCE AND TRUST COMPANY, A CORPORATION OF CALIFORNIA.

WIRELESS TRANSMISSION 01E ENERGY.

Continuation of application Serial No. 49,287, filed September 7, 1915. This application filed May 25, 1918. Serial No. 236,944.

To all tohontit may concern:

Be it known that I, EARL C. HANSON, a

citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Improvement in \Vn'eless Transmission of Energy, of which the following is a specification.

My invention relates to the transmission of energy by means of electro-static and electromagnetic induction from' place to place without the use of wires or other conducting members. It differs essentially from previous attempts at suchtransmission in that it employs waves at audio frequency rather than the common type of waves which are of radio frequency. The audio frequency elect-ro-static and electro-magnetic waves are those having a frequency within the range of the human car, this frequency being below ten thousand cycles per second. The advantages of using the audio frequency are First: The simplicity of the apparatus employed.

j a Second: The freedom from interference w th exist-mg radlo frequency 1n'stallatons.

Third: The freedom from atmospheric disturbances, and x I Fourth: The possibility of controlling the range of the apparatus employed,thus

allowing transmission to take place over limited distances without interference from or detection by similar apparatus outside the limited area. involved.

This application is a continuation of my application, Serial No. 49,287, filed Septem-.

her 7 1915. I

In the drawing I represent diagrammatically a complete sending and receiving sta tion. 'A single antenna 1- may be used, be-

ing connected to a switch 2 by means of which it may be connected to either a sending wire 3 or a receiving wire 4. Conncct-ed to the sending wire 3 1s a reactor 5 having an iron core 6, whose position may be varied at will to vary the amount of reactance in the circuit. A series of cont-acts 7, each' connected to a point in the winding of the reactor 5. is provided, and a movable arm 8 is also provided. so placed as to successively make contact with the contacts 7 by means of'which the number of turns in the reactor 5 may be varied. The reactor 5 is connected through a wire 9 to one termi- Specification of Letters Patent.

Patented Sept. 2, 1919.

nal of the high tension winding 10 of an iron core transformer, the other terminal this transmitter being int-urn shunted by variable condenser 17. The transmitter 16 is also connected through a wire 18 With one terminal of a battery 19 'which isalso shunted by a variable condenser 20. The

. other terminal of the battery 19 is connected through a wire 21 with a rheostat 22, which is in turn connected through a wire 23 with the other terminal of the low tension winding 13. The parts 5 to 2-3 inclusive form the sending apparatus above referred to.

The receiving wire 4 is connected through a movable arm 30 with any one of a series of contacts 31, each of which is connected to a. portion of the windingofa reactor 32,

this winding surrounding an iron core'33, i

the position of which .may be varied with relation to the winding so that the amount of reactance maybe Varied} The other terminal, of the reactor 32 is connected through a wire 34 with a switch 35, which is arranged to connect the wire 34 either.

.with a wire 36 or with a wire 37 The wire former 39 which forms a part of an amplifier, the other terminal of which winding is connected through a wire 49 with the ground 12. One terminal of the secondary winding of the transformer 39 is connected to the grid 43 of 'a vacuum bulb 40 which forms another part of the amplifier. and has a filament 41 heated bya battery 42. The grid 43 is in intimate relationship to a plate 44 which is connected by means of a wire 45 with abattery 46, the other terminal of. the battery 46 being connected through a wire 47 with atelephone receiver 48. The other terminal of the telephone receiver 48 is connected to the secondary of the transforn'ier 39 through a wire 50.

The method of operation of the apparatus is as follows: When it is desired to send a message, the. switch 2 is used to connect the wire 3'with the antenna -1.' With the apparatus so'con-,

, former.

nected, a current will flow from the battery 19 through the wire 18, transmitter 16, the Wire 15, low tension winding 13 of the transformer, the wire 23, the rheostat 22 and the Wire 21 back to the battery. This direct.

current being of practically constant strength will, of course, induce no current in the high tension winding 10. VVhe-never the operator speaks into the transmitter 16,

he will vary the resistance in the transmitter tween the antenna 1 and the ground 12, and

this will act through space through the medium of electro-static and electro-magnetic inductionon a similar antenna at the receiving station.

At the receiving station the switch-2 will be utilized to connect the antenna 1 to the receiving Wire 4:. This receiving wire will be connected to the Wire 34 through the reactor 32, the reaetance of which may be varied at will by moving the iron core 33 orvarying the number of turns in the winding or both. In some cases it will be sufficient to connect the Wire 34 with the wire 36 by means of the switch 35, the variations in intensity produced by the trans-:

mitter 16 being audible in the receiver 38 as audible speech. In other cases it is desirable to amplify these variations, in which case the wire 3-1 will be connected to the Wire 37 of the amplifier. This amplifier has-the property of acting as an extremely accurate and sensitive relay, and the faint currents introduced therein through the wire 37 serve to control much heavier currents produced by the battery 46, these heavier currents being readily audible in the receiver 48. The general theory of the amplifier is well understood and need not be gone into herein.

It will be seen that my invention employs iron core reactors both at. the sending and receiving stations. By the use of these reactors I am able to operate efficiently, us-

ingwave's of audio frequencies. Foreign vibrations which may be collected by the antenna 1 at the receiving station which are above this frequency are eliminated by the iron core 33 of the reactor 32. As a result parties using my invention may operate in close proximity to radio stations without interference with or from such stations. My invention is particularly useful '7 in signaling from trains, or incarrying on telephone conversations over short distances, such as, for example, from front to rear line trenches or from and toships and aeroplanes. By suitable regulation of the various parts, the area over which speech may be transmitted may be easily regulated.

The invention upon which this application is based is broader than the specific embodiment thereof which has been shown for the purpose of illustrating one of its uses, and I intend no limitations other than those imposed by the appended claims or by the art.

What I claim is:

1. The combination in an apparatus for transmitting audio-frequency energy through natural media, of sending means at the transmitting station for producing audio frequency energy, a receiving station comprising a responsive device, receiving means by which said energy actuates said responsive device and an iron core reactor in circuit with the responsive device.

2. A combination as in claim 1 in which the sending means includesan iron core reactor so placed as to eliminate radio frequency waves from the waves emitted from the sending station.

3. The combination in an apparatus for transmitting audio'frequcncy energy through natural media, of sending means at the transmitting station for producing audio frequency energy, an induction coil at the transmitting station, an earth connection to one terminal of .the secondary of the induction coil, "a conductor connected to the other terminal thereof through a variableiron core reactor, a receiving station com rising a responsive device, an earth connection to one terminal of the responsive device and a variable iron core reactorand a conductor connected to the other terminal of the responsivedevice;

4. The combination in an apparatus for transmitting audio frequency energy through natural media, .of sending means atthe transmitting station for producing audio frequency energy, a receiving station comprising means. for the reception of audio frequency energy, a vacuum tube amplifier, a responsive device connected with the amplifier, an earth connection to one terminal of the amplifier and an extended conductor connected to the other terminal through a variable iron core reactor.

The combination in an apparatus for transmitting audio frequency energy through natural media, of sending means at the transmitting station for producing audio frequency energy, a receiving station comprising means for the reception of audio frequency energy, a telephonic amplifier, a telephone receiver connected therewith, an earth connection to one tremiua-l of the amplifier and an extended conductor connected to the other terminal through a variable iron core reactor.

for receiving energy having a frequency not greatly in excess of speech frequency from natural media, a yacuum tube relay for amplifying said energy and a responsive device actuated by the amplified energy.

7. A wireless sending station adapted to oroduee ener 'v, havin a fre uency not be i C I greatly in excess of speech frequency, a receiving station comprising means for reproducing said energy, a vacuum tube relay amplifier and a responsive device actuated by the amplified energy.

8-. In a wireless receiving station, means for receiving energy having a frequency not greatly in excess of speech frequency from 15 natural media through an antenna, means including a vacuum tube for amplifying said energy and a responsive device actuated by the amphfied energy.

In testimony whereof, I have hereunto set 20 my hand at Los Angeles, Cahforma, this 16th day of May, 1918.

EARL C. HANSON. 

